The world of Linux is fascinating, and security is a crucial chapter of this journey. Fail2Ban is one of those essential tools for any Linux administrator concerned about protecting their servers. By monitoring system logs, it detects intrusion attempts on services such as SSH, HAProxy, or Postfix. And if an intruder becomes too persistent? Fail2Ban steps in, blocking the offender’s IP address via IPTables. One of the major strengths of Fail2Ban is its flexibility. You can create and tailor your own filters according to your needs. In this article, I will guide you through the installation and configuration of Fail2Ban on Debian.